Thread-forming apparatus.



' D. DREIER.

THREAD FORMING APPARATUS. APPLICATION FILED SEPT. 17, 1907. RENEWED JULY13, 1910.

Patented Jan. 17, 1911.

' Siam-r0 z, Jazzzkzbfimim HUI"IllIIUIHIIIW'IIHIIillllflllmllIUIIIIIIII!" DOMINIOK DREIER, 0F LIVINGSTON, MONTANA.

THREAD-FORMING APPARATUS.

Specification of Letters Patent.

Patented J an. 17, 19.11.

Application filed September 17, 1907, Serial No. 393,350. Renewed July13, 1910. Serial No. 571,845.

and without removal of metal from the stock, to effect formation ofthreads on an object, the metal forming the valleys of the threads beingcom iiressed whereby the stock is rendered more rigid in character.

lVith the above and other ol jects in view as will appear as the natureof the invention is better understood, the same consists, generallystated, in forming threads upon stock without removing any appreciableportion thereof, whereby the weakening that results in threading tubularstock is largely obviated.

The invention consists further in certain novel features of constructionand combination .of parts of a" threading device as will be hereinafterfully described and claimed.

In the accompanying drawings forming a part of this specification and inwhich like characters of reference indicate corresponding parts, Figure1 is a face view displaying the manner in which the forming members aredisposed when in operation. Fig. 2 is an enlarged detail view showing.the disposition of the cutter and of the chaser employed in connectiontherewith. Fig. 3 is a detail view showing the manner in which thethreads are formed upon the stock, and also the appearance. of the stockat the concl usion of the-threading operation.

Referring to the drawings. 1 designates a die holder, which may beeither the chuck of a threading machine or the holder of an ordinaryhand die stock. Carried by this member are three die carriers 2, 3 and twhich are of the usual construction.

The carrier Qis shown asequipped with an ordinary chaser or chasing die5 and with one of the threaders 6 which form the novelty of the presentinvention, while the carriers 3 and 4 are each provided only with athreader. As shown in Fig. -1, the chaser extends inwardly a shortdistance beyond the periphery of the threader, While, as shown in Fig.2, the chaser projects longitudinally some distance beyond the enteringend of the threader. The threaders 6 are tapered or cone-shapedstructures having peripheral ribs 7, which are disposed at right anglesto the long diameter of their carryingslu1fts 8, the small tapered endsof the thrcadcr being disposed at the mouth or entering end of the diestock.

In threading a pipe or other article with this threading device, thework is inserted and the chaser will first contact therewith and cut theinitial threads, and as the work is moved forward or as the die stock ismoved downward, as the case may be, the smallest of the ribs of thethreaders will enter the first thread, and operate progressively to drawthe work through the chuck or die stock and thereupon sink into themetal and form the thread, it being understood that the. axes of thethreaders are pitched at an angle of about one-half deg ee to the axisof the work, as shown in Fig. 2.

Owing to the tapered form of the threader 6 it will be. obvious that atthe conclusion of the threading operation there will be left someunfinished threads, as shown in Fig. 3, that is to say, threads that arenot the same depth as those at the entering end of the stock. This is ofadvantage, inasmuch as by having the stock slightly tapered at the pointwhere the threads cease, connection between the stock and coupling willbe of a more stable character.

lVhile but three of the threaders 6 are herein shown it will be obviousthat if desired a greater number may be employed and as this will bereadily appreciated detailed illustration thereof is omitted.

DOMINICK DREIER.

Witnesses:

E. M. NILES, ELBER'I F. ALLEN.

